Facile One-Step Synthesis of MPHMes from MesPCl₂ (M = Li, Na, K; Mes = 2,4,6-Me₃C₆H₂)

Abstract

Reaction of alkali metals (Li, Na, K) with mesityldichlorophosphane (MesPCl2, Mes = 2,4,6-Me3C6H2) in ethereal solvents leads to formation of the corresponding mesitylphosphanides MPHMes in good purity and yield. (31)P NMR spectroscopic studies in deuterated solvents strongly support a mechanism of the reaction that involves protonation/disproportionation steps in which the solvent is the only possible proton source. Li(thf)(tmeda)PHMes (1), [Na(tmeda)(μ-PHMes)]∞ (2), and [K(pmdeta)(μ-PHMes)]2 (3) (tmeda = N,N,N',N'-tetramethylethylenediamine, pmdeta = N,N,N',N″,N″-pentamethyldiethylenetriamine) were obtained; in the solid state, 2 forms zigzag chains while 3 is a dimeric compound.

B-substituted group 1 phosphides: synthesis and reactivity

“…The value correlates with those found in related sodium phosphides. 24 The B1–P1 bond length (2.061(4) Å) corresponds with those found in phosphido-borane complexes of alkali metals (ranging from 1.908(2) to 2.141(2) Å). 4 b ,24 e ,25…”

Synthesis, Structure, and Stability of Lithium Arylphosphanidyl‐diarylphosphane Oxide

“…However, the rubidium congener [(thf)Rb‐P(H)‐Tipp] ∞ shows a comparable wavy ladder structure . In contrast to this aggregation behavior, the smaller mesityl substituents lead to a three‐dimensional polymeric structure whereas three‐dentate pmdeta bases are able to stabilize dinuclear structures of the type [(pmdeta]K‐P(H)‐Mes] 2 . Larger terphenyl groups lead to lower aggregation degrees and the crown ether is even able to form mononuclear [(18‐C‐6) K‐P(H)‐Mes*] …”

“…[26] In contrast to this aggregation behavior, the smaller mesityl substituents lead to a three-dimensional polymeric structure [27] whereas three-dentate pmdeta bases are able to stabilize dinuclear structures of the type [(pmdeta]K-P(H)-Mes] 2 . [28] Larger terphenyl groups lead to lower aggregation degrees [29] and the crown ether is even able to form mononuclear [(18-C-6) K-P(H)-Mes*]. [30] The molecular structure and atom labeling scheme of 1,2bis(2,4,6-triisopropylphenyl)diphosphane (5) is depicted in Figure 3.…”

Phosphaindazole: A Phosphorus–Carbon Aromatic Heterocycle

“…We have recently reported a one‐step synthesis of alkali‐metal mesitylphosphanides MPHMes (Mes = 2,4,6‐Me 3 C 6 H 2 ) directly from the alkali metal and MesPCl 2 (M = Li, 10:4; M = Na, K, 6:2) in ethereal solvents 6. We observed that the formation of MPHMes (M = Na, K) is always accompanied by the formation of a small amount of a side product, which was isolated and identified as [{Na(1,4‐dioxane) 2 (μ‐P 2 C 9 H 9 ‐κ P )} 2 (μ‐1,4‐dioxane)] ∞ ( 1 ) (yellow crystals, 11 % yield, containing a small amount of NaPHMes, see the Supporting Information) and [K(pmdeta)(μ‐P 2 C 9 H 9 ‐κ 2 P , P′ )] ∞ ( 2 ) (pmdeta = NMe 2 CH 2 CH 2 NMeCH 2 CH 2 NMe 2 ) (yellow crystals, 20 % yield, see the Supporting Information) containing a novel phosphorus–carbon heterocycle: phosphaindazole, the phosphorus analogue of indazole7 or diphosphaindene, the phosphorus analogue of indene (Scheme ).…”

“…In the synthesis of alkali‐metal mesitylphosphanides MPHMes6 (Scheme ), in which phosphaindazole was obtained as a side product, (P 2 Mes 2 ) 2– is observed as an intermediate and could be a suitable starting material for the formation of phosphaindazole.…”